David's guitar is a Gibson for sure
Stills and Young on Gretsch White Falcons (one of my all time fav looking guitars) Crosby is on some kind of Gibson archtop but it could be a Guild. Not sure what Nash's acoustic is but it looks like a custom Gibson. Great pic, looks very intense.
Stills and Young may be sharing the same type of guitar but Crosby's just looks similar... it's a different guitar. also, this is a really good picture!
three of the same guitars? interesting.
this is an awesome pic indeed.